Mechanism for actuating the slay of a weaving loom

ABSTRACT

An articulated joint mechanism transmitting to the slay of a weaving loom a reciprocating motion with a delay in one of its extreme positions sufficient for picking the weft through the shed even at a high rotating speed of the drive and with woven fabrics of large width, the mechanism providing in one extreme position of the slay a negligible angular travel of the slay during a large angular travel of a rotating crank element, which drives the mechanism.

United States Patent Dvoracek et al.

MECHANISM FOR ACTUATING THE SLAY OF A WEAVING LOOM Inventors: Pavel Dvoracek, Brno; Jaromir Malasek, Ostrava; Vladimir Kuda; Adolf Slezak, both of Brno, all of Czechoslovakia Assignee: Vyzkumny a vyvojovy ustav Zavodu vseobecneho strojirenstvi, Brno, Czechoslovakia Filed: Apr. 6, 1972 Appl. No.: 241,778

Foreign Application Priority Data July 12, 1971 Czechoslovakia 5088-71 US. Cl. 139/190 Int. Cl...- D03d 49/64 Field of Search 139/188, 190, 191, 123

1 1 Jan. 7, 1975 [56] References Cited UNITED STATES PATENTS 3,378,042 4/1968 Fransen 139/190 3,735,783 5/1973 Fritz et a1. 1. 139/123 FOREIGN PATENTS OR APPLICATIONS 1,026,303 2/1953 France 139/190 Primary ExaminerHenry S. Jaudon [57] ABSTRACT An articulated joint mechanism transmitting to the slay of a weaving loom a reciprocating motion with a delay in one of its extreme positions sufficient for picking the weft through the shed even at a high rotat ing speed of the drive and with woven fabrics of large width, the mechanism providing in one extreme position of the slay a negligible angular travel of the slay during a large angular travel of a rotating crank element, which drives the mechanism.

3 Claims, 5 Drawing Figures PATENTED SHEET 2 OF 2 MECHANISM FOR ACTUATING THE SLAY OF A WEAVING LOOM BACKGROUND OF THE INVENTION The object of this invention is the provision of an arrangement of an articulated joint mechanism for actuating the slay of looms, particularly of air-jet or waterjet looms.

The slay, which carries a reed for guiding warp threads and for beating up the weft to the fell, forms generally a part of the weaving loom. In air-jet looms it frequently also carries part of the shuttle device for introducing the weft into the shed. In the course of weaving the slay reciprocates: this motion in one extreme position requires a delay for picking the weft through the shed. A sufficiently long delay of this reciprocating motion is particularly important for weaving looms operating at high rotating speeds or having a larger width of the fabric in order to secure a perfect picking of the weft. The movement of the slay is usually derived from the main shaft of the loom and the magnitude of the delay is in fact a fraction of one turn of the main shaft of the loom. This delay of the motion of the slay is therefore reduced if the speed of rotation of the main shaft is increased. The time interval required for a perfect picking of the weft is determined by the optimum picking speed of the weft and by the picking length, that is, by the width of the fabric. When increasing the speed of the loom and increasing the width of the fabric, a situation may arise wherein the delay of the motion of the slay, determined by the design of the actuating mechanism of the slay, is smaller than the minimum time interval required for picking the weft for the given width of fabric and thus the correct picking of the weft is impossible. Actuating mechanisms for slays having the longest delay possible are therefore sought after.

Known actuating mechanisms for slays of weaving looms are generally articulated joint mechanisms frequently having six elements. They usually have a crank or a crank shaft connected by a connecting rod to a rocker lever, the lever itself being connected over a pitman with a slay arm carrying the slay.

A major drawback of known arrangements of similar mechanisms is the short delay in the reciprocating motion of the slay. The delay usually corresponds to less than 140 of one revolution of the crank of the mechanism. It is obvious that this delay can be prolonged by the addition of further articulated joint elements so that a system of eight or more elements is obtained. A drawback of similar articulated joint mechanisms is their insufficient rigidity, play in the joints, and thus an instability of the whole mechanism. The inertia mass is also increased, thereby impairing the dynamic properties of the mechanism and increasing the space requirements for the loom.

Other known arrangements for actuating slays are cam mechanisms in which the reciprocating swinging motion of the slay is derived from one or more cams. A drawback is their relatively short useful life. In addition the manufacture and checking of the correct shape of the cam is demanding and requires that the manufacturer have much experience and technological skill.

SUMMARY OF THE INVENTION It is an object of this invention to eliminate these drawbacks and to provide an improved articulated joint mechanism for actuating slays of weaving looms, which prolong the delay of the reciprocating movement of the slay without increasing the weight of the mechanism and without reducing its rigidity as compared to prior actually used similar mechanisms.

According to this invention the fulcrum axis of the connection of the rocker lever with the connecting rod is located on a circle in at least one position of the operating element in the course of the delay of its reciprocating movement, the diameter of the circle being the line connecting the axis of the pivotal support of the rocker lever and of the axis of rotation of the crank element. As a result, the fulcrum axis of the pitman and of the operating element is located on a circle in at least at one position of the operating element in the course of the delay of its reciprocating movement, the diameter of the latter circle being the line the connecting of the axis of the pivotal support of the rocker lever and of the axis of the pivotal support of the operating element.

Another feature of this invention is that the fulcrum axis of the connection of the rocker lever with the connecting rod is located on a circle in the extreme position of the operating element in the course of the delay of its reciprocating movement, the diameter of the last circle being the line connecting the axis of the pivotal support of the rocker lever and of the rotation axis of the crank element, and the fulcrum axis of the pitman and of the operating element is on a circle, the diameter of which is the line connecting the axis of the pivotal support of the rocker lever and the pivotal axis of the operating element when the operating element is in the middle position of the delay of its reciprocating movement.

A still further feature of this invention is that the rotation axis of the crank element may be made coincident with the pivotal support of the operating element.

By the arrangement of the actuating mechanism for the slay of a weaving loom according to this invention, it is possible to achieve a high degree of nonuniformity of the movement of the slay, that is, long delays of the swinging motion of the slay in its extreme position corresponding to the picking of the weft. This permits the use of a new mechanism for actuating the slay, which mechanism is lighter, simpler and more convenient for different purposes, thereby permitting the use of high speeds of the weaving loom even in cases of increased widths of the fabric.

DESCRIPTION OF THE DRAWINGS Further advantages and features of this invention will be apparent from the following description with the attached drawings, wherein FIG. I is a schematic side view of a weaving loom in partial section,

FIG. 2 is a schematic elevation of one examplary embodiment of the actuating mechanism for the slay,

FIG. 3 is a schematic outline of this mechanism,

FIG. 4 is another example of an actuating mechanism of the slay; and

FIG. 5 is a schematic view of a further embodiment of actuating mechanism in accordance with the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS A first examplary embodiment of a weaving loom with means for actuating the loom according to this invention is shown in FIG. 1. The frame 1 with two side walls 2 supports all the driving means of the loom. A rotatable warp cylinder 3 is situated in the front part of the loom between the side walls 2, from which warp cylinder 3 the warp threads 4 are guided over a yarn rest 5 and back rails 6. The warp threads 4 form a shed 8 in the currently used way by means of healds 7. The woven fabric 9 at the beat-up place 10 is beaten by the reed 11 in the customary manner. The fabric 9 passes behind the beat-up place 10 over stretchers 12 to the breast beam 13, and subsequently over the take-off roller 14 having pressure rollers 15, 16 to the storage roller 17.

The driving mechanism proper is concentrated into the space between the side walls 2 of the loom. The mechanism for actuating the slay is driven by an electric motor 18 which causes the rotation of a main shaft 20 by way of transmission 19. The main shaft 20 is provided with a crank element 21 which is part of the mechanism proper for actuating the slay, which mechanism forms an articulated joint mechanism with six elements, comprising the already mentioned crank element 21, a connecting rod 22, a rocker lever 23, a pitman 26 and an operating element 27.

As is indicated in more detail in FIG. 2, the connecting rod 22 is supported pivotally at one end by a bolt 28 of the crank element 21 and at its other end is connected by a joint 29 with one arm 24' of a rocker lever 23. The rocker lever 23 is pivotally supported on the stable part of the frame 1 of the loom by a bolt 30, The other arm of the rocker lever 23 is connected pivotally by means of a joint 31 with a pitman 26 which, in turn, is pivotally connected by means of a bolt 32 to the operating element 27. The operating element 27 is pivotally supported on a fixed part of the frame 1 by a bolt 33 and, in the embodiments shown in FIGS. 1 and 2 a two arm lever. One arm 34 serves for a pivotal connection with the pitman 26, whereas the second arm, the slay arm 35, carries the slay 36 with the reed 11 for beating up the picked-through weft against the fabric The mechanism operates as follows the rotatable motion of the crank element 21 is transmitted via the connecting rod 22 to a rocking motion of the rocker lever 23. This rocking motion is transmitted by the pitman 26 to the operating element 27. Due to the transmission of the motion of the connecting rod 22 by way of the rocker lever 23 and the pitman 26, the rocking movement of the operating element 27 becomes nonuniform. At the moment of the delay, that is, in one extreme position of the slay 36, the picking of the weft is performed by a known arrangement (not shown). The reed 11 beats up the picked through weft against the fabric 10 in the other extreme position of the slay 36. This operation is repeated at each revolution of the main shaft 20 of the loom.

According to the arrangement shown in FIG. 3, the actuating mechanism of the slay 36 is arranged so that the angular displacement ill of the crank element 21 of the main shaft corresponds to a sufficiently small angular displacement Ill of the rocking movement of the operating element 27 and also of the slay 36. If the operating element 27 has in this delay position been displaced through an angle corresponding to the angular displacement ill, the axis 38 of the pivotal connection of the pitman 26 with the operating element 27 is displaced on the circle k. The circle k is circumscribed over the connecting line 41 of the axis 39 of the pivotal support of the rocker lever 23 and of the axis 40 of the pivotal support of the operating element 27, whereby the axes 39, 40 simultaneously determine the diameter of this circle k. In the examplary embodiment according to FIG. 3, axis 38 of the pivotal connection of the pitman 26 with the operating element 27 is in the position indicated by broken lines on the circle k throughout one half of the angular displacement (l1 corresponding to the delay.

The line 42 connecting the axis 39 of the pivotal support of the rocker lever 23 and of the rotation axis 43 of the crank element 21 determines the diameter over which a second circle 1 is circumscribed. The axis 44 of the pivotal connection of the rocker lever 23 and of the connecting rod 22 is on this circle 1 if the operating element 27 is in a position within the angle 11! corresponding to the delay of the slay. In the position indicated in FIG. 3 by full lines the operating element 27 is illustrated in one extreme position within the angle ll! representing the delay.

Another possible arrangement of the mechanism is shown schematically in FIG. 4. The same principles as for the above described arrangements apply here, with the difference that the operating element 24 is pivotally supported coaxially with the axis of rotation 43 of the crank element 21 of the mechanism. The circles k and l of the embodiment of FIG. 3 merge to a single circle m. This arrangement of the mechanism is simpler and requires less space.

There are, of course, numerous other alternatives of the mechanism according to this invention. FIG. 5 shows, for instance, an actuating mechanism for the slay 36, the rocker lever 23 of which represents a single-arm lever, one and of which is pivotally supported on the fixed frame l and the other end being pivotally connected to both the connecting rod 22 and to the pitman 26 of the mechanism.

The mechanism according to this invention can be used for all types of weaving looms, and is particularly advantageous for looms operating at higher rotating speeds and manufacturing fabrics of larger width.

We claim:

1. An articulated joint mechanism for transmitting to the slay of a weaving loom a reciprocating motion derived from a uniform rotating motion with a delay of the motion of the slay in one of the extreme positions of its reciprocating movement sufficient for picking the weft through the shed, said mechanism comprising a rotating crank element, a rocker lever and an operating element carrying the slay of the loom, means for supporting the crank element for rotation, means for pivotally supporting the rocker lever and the operating element, a connecting rod linking the crank element with the rocker lever, a pitman linking the rocker lever with the operating element, the fulcrum axis of the connection of the rocker lever with the connecting rod lying on a circle in at least one position of the operating element in the course of the delay of its reciprocating movement, the diameter of said circle being the line connecting the axis of the pivotal support of the rocker lever and the axis of rotation of the crank element, whereby the axis of the fulcrum of the pitman and of the operating element is in at least one position of the operating element in the course of the delay of its reciprocating movement located on a second circle, the

diameter of said second circle being the line connecting the axis of the pivotal support of the rocker lever and the axis of the pivotal support of the operating element.

2. A mechanism as set forth in claim 1, wherein the fulcrum axis of the connection of the rocker lever with the connecting rod is in the extreme position of the operating element in the course of the delay of its reciprocating movement on a circle the diameter of which is the line connecting the axis of the pivotal support of the rocker lever and the axis of rotation of the crank element, and the fulcrum axis of the pitman and of the 0perating element is on a circle the diameter of which is the line connecting the axis of the pivotal support of the rocker lever and of the pivotal axis of the operating element when the operating element is in the middle position of the delay of its reciprocating movement.

3. A mechanism as set forth in claim 1, wherein the axis of the rotating movement of the crank element is coincident with the axis of the pivotal support of the operating element. 

1. An articulated joint mechanism for transmitting to the slay of a weaving loom a reciprocating motion derived from a uniform rotating motion with a delay of the motion of the slay in one of the extreme positions of its reciprocating movement sufficient for picking the weft through the shed, said mechanism comprising a rotating crank element, a rocker lever and an operating element carrying the slay of the loom, means for supporting the crank element for rotation, means for pivotally supporting the rocker lever and the operating element, a connecting rod linking the crank element with the rocker lever, a pitman linking the rocker lever with the operating element, the fulcrum axis of the connection of the rocker lever with the connecting rod lying on a circle in at least one position of the operating element in the course of the delay of its reciprocating movement, the diameter of said circle being the line connecting the axis of the pivotal support of the rocker lever and the axis of rotation of the crank element, whereby the axis of the fulcrum of the pitman and of the operating element is in at least one position of the operating element in the course of the delay of its reciprocating movement located on a second circle, the diameter of said second circle being the line connecting the axis of the pivotal support of the rocker lever and the axis of the pivotal support of the operating element.
 2. A mechanism as set forth in claim 1, wherein the fulcrum axis of the connection of the rocker lever with the connecting rod is in the extreme position of the operating element in the course of the delay of its reciprocating movement on a circle the diameter of which is the line connecting the axis of the pivotal support of the rocker lever and the axis of rotation of the crank element, and the fulcrum axis of the pitman and of the operating element is on a circle the diameter of which is the line connecting the axis of the pivotal support of the rocker lever and of the pivotal axis of the operating element when the operating element is in the middle position of the delay of its reciprocating movement.
 3. A mechanism as set forth in claim 1, wherein the axis of the rotating movement of the crank element is coincident with the axis of the pivotal support of the operating element. 